1. Field of the Invention
The present invention relates to methods for fabricating composite materials and, particularly, to a method for fabricating a magnesium-based carbon nanotube composite material.
2. Discussion of Related Art
Nowadays, various alloys have been developed for special applications. Among these alloys, magnesium alloys have relatively superior mechanical properties, such as low density, good wear resistance, and high elastic modulus. However, the toughness and the strength of the magnesium alloys are not able to meet the increasing needs of the automotive and aerospace industry for tougher and stronger alloys.
To address the above-described problems, magnesium-based composite materials have been developed. In the magnesium-based composite material, nanoscale reinforcements (e.g. carbon nanotubes and carbon nanofibers) are mixed with the magnesium metal or alloy. The most common methods for making the magnesium-based composite material are through thixomolding and die-casting. However, in die-casting, the magnesium or magnesium alloy is easily oxidized. In thixomolding, the nanoscale reinforcements are added to melted metal or alloy and are prone to aggregate. As such, the nanoscale reinforcements can't be well dispersed.
What is needed, therefore, is to provide a method for fabricating a magnesium-based carbon nanotube composite material, in which the above problems are eliminated or at least alleviated.